Spectroscopic Classification of ASASSN-17oh, ASASSN-17on, and ASASSN-17os with du Pont
ATel #10957; N. Morrell (LCO), J. L. Prieto (UDP/MAS), S. Dong (KIAA/PKU), B. J. Shappee (IfA Hawaii)
on 12 Nov 2017; 21:35 UT
Credential Certification: Jose L. Prieto (jose.prietok@mail.udp.cl)
Subjects: Optical, Supernovae, Transient
We obtained low-resolution optical spectra (range 3600-9600 Angs., FWHM res ~ 8 Angs.) of ASASSN-17oh/AT2017hxj, ASASSN-17on/AT2017hya, and ASASSN-17os/AT 2017hyy on UT 2017 Nov. 12.2 with WFCCD mounted on the du Pont 2.5m at Las Campanas Observatory. ASASSN-17oh shows broad Balmer lines (H-alpha FWHM~12000 km/s) with weak P-Cygni profiles characteristic of a Type II SN caught relatively early. ASASSN-17on shows features characteristic of a Type Ia SN around peak (including the Si II line) with very strong host-galaxy contamination. ASASSN-17os shows a blue continuum with a large number of narrow (but resolved) lines (FWHM~1000-1500 km/s) in emission from H I (Balmer features), He I, He II, N II, and possibly others. The presence of a blue continuum and H I is consistent with a young Type II SN, but the subtype is uncertain.